Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds useful context by saying the response includes "every public field plus its page URL", which matters since there's no output schema. It omits what happens on a miss (error vs empty), keeping it from a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One tight sentence with the resource first, the key second, and the return shape last. Nothing is padded or repeated.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter read with no output schema, telling the agent the response is the full public record plus page URL is nearly sufficient. Only the not-found behavior and the exact-name matching fallback are unstated.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the slug definition already explains the format and example, so the schema carries the load. The description's "(or exact name)" restates what the schema already documents, adding no new syntax or matching-rule detail. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a concrete verb and resource ("Get one listed company") and the lookup key (slug or exact name), plus what comes back. It implicitly distinguishes itself from list/grid siblings like search_startups by emphasizing a single record, though it never names an alternative.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The "from search results" hint in the schema and "slug" in the description imply the intended flow (search first, then fetch by slug), but the description itself gives no explicit when-to-use or when-not guidance and doesn't reference search_startups or check_if_listed.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.